1. Field of the Invention
The present invention relates to an active feedback control integrated circuit applied to an alternating current/direct current converter and an operation method thereof, and particularly to an active feedback control integrated circuit and an operation method thereof that can decrease power loss of the active feedback control integrated circuit, a switch of a primary side of the alternating current/direct current converter, and an output feedback unit of a secondary side of the alternating current/direct current converter by decreasing a current flowing through a feedback pin of the active feedback control integrated circuit in a burst mode or a deep sleep mode.
2. Description of the Prior Art
Nowadays, a portable consumer electronic product designer needs to utilize some power saving technologies to extend a standby time of portable consumer electronic products, where decreasing standby time power consumption is the most important power saving technology of the power saving technologies.
When a portable consumer electronic product is in a light lode mode or a standby time mode, an active feedback control integrated circuit, a switch of a primary side, and a photo coupler of an alternating current/direct current converter of the portable consumer electronic product still generate very large power loss. Because the portable consumer electronic product is in the light lode mode or the standby time mode for a long time, decreasing the power loss of the active feedback control integrated circuit, the switch of the primary side, and the photo coupler can significantly decrease standby time power consumption of the portable consumer electronic product.
For decreasing the standby time power consumption of the portable consumer electronic product, the prior art increases impedance of a COMP pin of the active feedback control integrated circuit to decrease operation current and a burst frequency of a pulse width modulation signal which is used for controlling turning-on and turning-off of the switch of the primary side of the active feedback control integrated circuit. However, when the portable consumer electronic product is in the standby time mode, the alternating current/direct current converter still operates in a close loop, so the power loss of the active feedback control integrated circuit, the switch of the primary side, and the photo coupler is higher than the power loss of the active feedback control integrated circuit, the switch of the primary side, and the photo coupler when the alternating current/direct current converter operates in an open loop, and the portable consumer electronic product has slower transient response.